What triggers the release of BNP hormone?

The release of B-type natriuretic peptide (BNP) is primarily triggered by high ventricular filling pressure. This peptide is produced by the cardiac ventricles in response to increased stretch of the heart muscle, which occurs when the heart is unable to adequately pump blood, leading to elevated pressures and volume overload.

When the ventricles experience higher filling pressures, the myocardial cells respond by secreting BNP as a compensatory mechanism. The hormone plays a key role in promoting natriuresis (the excretion of sodium through urine) and diuresis (increased urine production), helping to reduce fluid overload and lower blood pressure. Thus, the primary stimulus for BNP release is the mechanical stretch experienced by ventricular cells related to increased volume or pressure.

In contrast, low oxygenation levels, increased heart rate, and high blood pressure do not directly stimulate the secretion of BNP. Instead, these factors may influence cardiac function or stress the heart in different ways, but they are not the immediate triggers for BNP release in the same manner that high ventricular filling pressure is. This distinction highlights the specific role of BNP as a response to volume overload rather than a direct response to other factors that affect heart function.